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    Measles(麻疹), which once killed 450 children each year and disabled even more, was nearly wiped out in the United States 14 years ago by the universal use of the MMR vaccine(疫苗). But the disease is making a comeback, caused by a growing anti-vaccine movement and misinformation that is spreading quickly. Already this year, 115 measles cases have been reported in the USA, compared with 189 for all of last year.

    The numbers might sound small, but they are the leading edge of a dangerous trend. When vaccination rates are very high, as they still are in the nation as a whole, everyone is protected. This is called “herd immunity”, which protects the people who get hurt easily, including those who can't be vaccinated for medical reasons, babies too young to get vaccinated and people on whom the vaccine doesn't work.

    But herd immunity works only when nearly the whole herd joins in. When some refuse vaccination and seek a free ride, immunity breaks down and everyone is in even bigger danger.

    That's exactly what is happening in small neighborhoods around the country from Orange County, California, where 22 measles cases were reported this month, to Brooklyn, N.Y., where a 17-year-old caused an outbreak last year.

    The resistance to vaccine has continued for decades, and it is driven by a real but very small risk. Those who refuse to take that risk selfishly make others suffer.

    Making things worse are state laws that make it too easy to opt out(决定不参加) of what are supposed to be required vaccines for all children entering kindergarten. Seventeen states allow parents to get an exemption（豁免), sometimes just by signing a paper saying they personally object to a vaccine.

    Now, several states are moving to tighten laws by adding new regulations for opting out. But no one does enough to limit exemptions.

    Parents ought to be able to opt out only for limited medical or religious reasons. But personal opinions? Not good enough. Everyone enjoys the life-saving benefits vaccines provide, but they'll exist only as long as everyone shares in the risks.

    NANJING, Nov. 4 (Xinhua) — Xi Jinping and Ma Ying-jeou will shake hands in their historic meeting scheduled in Singapore on Saturday, head of the Taiwan Affairs Office of the State Council said on Wednesday.

    The two-part meeting includes one session open to the media and another behind closed doors, said Zhang Zhijun, who is also head of the Taiwan Work Office of the Communist Party of China (CPC) Central Committee, when interviewed at the Zijinshan Summit for Entrepreneurs across the Taiwan Strait.

    According to Zhang, Xi and Ma, as "leaders of the two sides" of the Taiwan Strait, will exchange views during the closed-door meeting.

    After the meeting, press conferences will be held by both sides. Later, the two leaders are expected to attend a dinner, said Zhang.

    Zhang said the meeting will lift cross-Strait communication to a new high.

The landmark meeting is a breakthrough in face-to-face exchange and communication between the leaders across the Taiwan Strait after the relationship became strained following the events of 1949.

    Zhang said the meeting will improve mutual trust and allow for an exchange of opinions on handling the cross-Strait ties.

    In addition, the meeting will help strengthen the 1992 Consensus(共识), which was reached in talks between the two sides in 1992 and recognizes the one-China principle, and safeguards the peaceful development of cross-Strait ties, according to Zhang.

    Zhang added that the scheduled meeting will also benefit regional peace and stability.

    Also at Wednesday's summit, Chiang Pin-kung, former chairman of the Taiwan-based Straits Exchange Foundation, hailed the upcoming meeting between the two leaders as a milestone for cross-Strait ties.

    Chiang told the media that he believed the meeting will give a boost to the peaceful development of cross-Strait ties.

    It's generally believed that people act the way they do because of their personalities and attitudes. They recycle their garbage because they care about the environment. They pay $5 for a caramel brulee latte because they like expensive coffee drinks.

    It's undeniable that behavior comes from our inner dispositions（性情）,but in many instances we also draw inferences about who we are,as suggested by the social psychologist Daryl Bern,by observing our own behavior.We can be strangers to ourselves.If we knew our own minds,why would we need to guess what our preferences are from our behavior?If our minds were an open book,we would know exactly how much we care about the environment or like lattes.Actually,we often need to look to our behavior to figure out who we are.

    Moreover,we don't just use our behavior to learn about our particular types of character—we infer characters that weren't there before.Our behavior is often shaped by little pressures around us,which we fail to recognize.Maybe we recycle because our wives and neighbors would disapprove if we didn't.Maybe we buy lattes in order to impress the people around us.We should not mistakenly believe that we always behave as a result of some inner disposition.

    Whatever pressures there can be or inferences one can make,people become what they do,though it may not be in compliance（符合）with their true desires.Therefore,we should all bear in mind Kurt Vonnegut's advice:"We are what we pretend to be,so we must be careful about what we pretend to be."

    For teenagers, it's great fun to explore new places and it feels like an adventure, even when you know you're not the first to have been there. But to make sure not to get lost or waste time going round in circles, the following tips may be helpful.

    Do the map reading if you're being driven somewhere. It'll be easier if you keep the map following the direction you are traveling in. Keep looking ahead so that you can give the driver lots of warning before having to make a turn, or you'll have to move to the back seat.

    Get a group of friends together and go exploring. You'll need a good map, a compass , a raincoat, a cell phone to call for help in case you get lost, and a bit of spare cash for emergencies .Tell someone where you're going before you set out and let them know what time you expect to be back. The purpose of the activity is in not getting lost, not in seeing how fast you can go, so always stick together, waiting for slower friends to catch up.

    See if your school or a club organizes orienteering（越野识途比赛）activities, in which you need a map and a compass to find your way. This can be done as a sport, with teams trying to find the way from A to B(and B to C, etc. ) in the fastest time, or simply as a spare-time activity. It enables you to be familiar with the use of maps and compass and gain some special skills. In some way, it's not only good fun, but also a great way to keep fit.

    Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity (湿度).

In very cold climates, there is a constant danger of developing hypothermia, which is a life-threatening drop in core body temperature to below normal levels. The normal temperature for humans is about 37.0℃. However, differences in persons and even the time of day can cause it to be as much as 6℃ higher or lower in healthy individuals. It is also normal for core body temperature to be lower in elderly people. Hypothermia begins to occur when the core body temperature drops to 34.4℃. Below 29.4℃, the body cools more rapidly because its natural temperature regulating system usually fails. The rapid decline in core body temperature is likely to result in death. However, there have been rare cases in which people have been saved after their temperatures had dropped to 13.9-15.6℃. This happened in 1999 to a Swedish woman who was trapped under an ice sheet in freezing water for 80 minutes. She was found unconscious, not breathing, and her heart had stopped beating, yet she was eventually saved despite the fact that her temperature had dropped to 13.7℃.

In extremely hot climates or as a result of uncontrollable infections, core body temperatures can rise to equally dangerous levels. This is hyperthermia. Life-threatening hyperthermia typically starts in humans when their temperatures rise to 40.6-41.7℃. Only a few days at this extraordinarily high temperature level is likely to result in the worsening of internal organs and death.

    Many of us think, wrongly, that the moon doesn't change. For example, the Tang Dynasty poet Zhang Ruoxu once wrote that "Generations have come and passed away; From year to year the moons took alike, old and new."

    However, a new study published in the journal Nature Geoscience shows that the moon is in fact slowly shrinking over time. For the study, a group of US scientists examined and analyzed thousands of photographs taken by the NASA orbiter Lunar Reconnaissance Orbiter Camera (月球勘测轨道飞行器照相机) . They found that there were lots of faults (断层) on the surface of the moon. These faults were formed by recent movement on the moon.

    According to NASA, the moon is made up of pieces of rocks with a hot core (核) .The moon continued to expand as it was born. But in this process, it released energy and cooled down. Then it began to shrink, in a way comparable to the shrinking of a grape into a raisin (葡萄干) . Over the past several hundred million years, it has become 46 meters "skinnier". But due to its hard and rocky crust (外壳) . the moon's surface continues to push up, "Some of these quakes can be fairly strong around five on the Richter scale (里氏震级) ," said Thomas Watters, a senior scientist at the Smithsonian's National Air and Space Museum in the US.

    But does that mean the moon is a dangerous place that human shouldn't try to explore and live on in the future? Maybe not, reported the Telegraph, "This isn't anything to worry about. The moon may be shrinking, but not by much. It's not going anywhere," Watters comforted us.

    The new discovery proves that the idea that the moon is a dead, boring place is wrong. "We have been to the moon and we've done some great science, but there is still a lot we don't know. The moon is shrinking ­ we didn't really realize that until recently. It's a much more active and interesting place than we thought and we should explore that," NASA scientist Nathan Williams said.